Plate and fin type heat exchangers typically have a core comprising a plurality of flat tubes for carrying a liquid coolant. The tubes are arranged in a stack, with spaces being provided between the tubes for circulation of air. Corrugated cooling fins may be provided between adjacent plate pairs to enhance heat transfer from the coolant to the air. The cooling fins are made from very thin metal sheet material or foil, and are susceptible to damage. Also, in many cases the side walls of the cooling fins are provided with perforations or louvers to enhance their performance, however, the presence of these perforations can make the cooling fin more delicate and increase its susceptibility to damage.
In one particular application, the inventors have found that the presence of an air flow stream, such as a bypass flow, about the ends of a heat exchanger core, in contact with the sides of the fins, can result in cracking or partial destruction and loss of portions of the fins. While it may be desirable to eliminate bypass flow or other air flow about the ends of the heat exchanger core, it is not always feasible to do so. Therefore, there is a need for means to prevent damage to cooling fins which do not rely solely on the elimination of bypass air flow.